The long-term aim of this project is to use anatomical magnetic resonance imaging (MRI) to understand better the neural basis of childhood neuropsychiatric disorders. This particular application will focus on defining the anatomical basis of Tourette's syndrome (TS), Obsessive-Compulsive Disorder (OCD), and Attention Deficit Hyperactivity Disorder (ADHD). Detailed volumetric and morphological measures of precisely defined cortical and subcortical regions in 620 children and adults will be compared across age and diagnostic groups. Correlates of these measures with immunological, neurohumoral, neuropsychological, and family history data, and with other behavioral indices, will be assessed. Both manual and automated image analysis methodologies will be applied for the improved assessment of brain morphology. By understanding the disturbances in cerebral architecture that undedie these developmental disorders and how they give rise to associated behavioral disturbances in these conditions, we will be better able to assess and to time the efficacy of therapeutic interventions in the context of the developing nervous system. [unreadable] [unreadable]